Brüel & Kjær 2007 User guide
·
Instructions
.-
and
Applications
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Heterodyne Voltmeter
Type 2007
A portable, mains
or
battery operated
instrument with voltage ranges
from
10
fA-
V to 100 V, covering
the
100 kHz to
305
MHz frequency
ranges
for
carrier
or
modulation
measurements on AM
or
FM
signals.
Features include a peak
diode
detector
for
TV measurements,
manual
or
remote voltage controlled
frequency tuning, a
built
in loud-
speaker
for
easy signal identification
and
self
contained rechargeable
batteries and charger.
HETERODYNE VOLTMETER TYPE 2007
August 1972
CONTENTS
1.
INTRODUCTION
......................................
5
2.
CONTROLS
...............
~
..........................
6
2.1. Measurement Probe and Probe Accessories
..........
6
2.2.
Front
Panel
of
2007
...........................
8
2.3.
Rear
Panel
of
2007 . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3. OPERATION
.........................................
16
3.1. Preliminary
...............
.
...............
16
Operation Using Mains
or
Line Voltage Supply
.....
16
Operation Using the
Built-in
Battery Supply
.......
16
3.2. Reference Adjustments . . . . . . . . . . . . . . . . . . . . . . . . 17
3.3. RF Carrier Voltage Measurements . . . . . . . . . . . . . . . 18
3.4.
Modulation
Measurements
....................
.
20
Using Heterodyne
Voltmeter
Type
2007
..........
20
Using Heterodyne
Voltmeter
Type
2007
with
a
Measuring
Amplifier
..
.
.......................
21
3.5.
Distortion
Measurements
...
'
..................
. 22
3.6.
Use
of
Remote Tuning and Ext. Batt. Socket
.......
23
Remote Frequency Tuning
.....................
24
Operation Using
an
External Battery
.............
26
Carrier Detector
Output
. . . . . . . . . . . . . . . . . . . . . . .
28
LF
Output
.................................
28
4. DESCRIPTION
..................................
."
....
30
4.1. Measurement Probe
..........................
30
4.2. Heterodyne
Voltmeter
........................
31
Input
Section
...............................
31
Frequency Selective Section . . . . . . . . . . . . . . . . . . . . 32
Detection and
LF
Amplification
.......
.
.........
34
Power Supply
...............................
35
5.
APPLICATIONS
......................................
36
5.1. Antenna
Distribution
Systems
..................
36
Signal Strength
and
Transmission
Loss
............
36
Cross-Talk
........
..
........................
38
IntermoduIation
Distort
ion . . . . . . . . . . . . . . . . . . . .
39
Amplifier
Sensitivity
to
Mains Noise
..............
40
5.2. Antenna Measurements
........................
41
Use
as
a Field Strength Meter . . . . . . . . . . . . . . . . . . .
41
Directivity
of
Receiving Antennas
...............
42
5.3. Checking
Output
of
a Signal Generator
...........
44
5.4. Measurement
of
Output
Impedance
..............
46
5.5.
Automatic
Recording
of
Modulation Response
......
47
6.
SPECIFICATIONS
.....................................
50
1.
INTRODUCTION
The Heterodyne
Voltmeter
Type 2007
is
a portable, completely self-
contained, precision instrument, designed
for
voltage, frequency and
modulation measurements on radio frequency signals.
It
is
basically a high
quality
super heterodyne receiver
with
an
AM
detector and FM discriminator
for
measurements on amplitude and
frequency modulated signals
and
apeak diode detector
for
measurements
on
TV
signals. The heterodyne section
of
the instrument features voltage
controlled
tuning
over eight frequency
ranges
covering
100kHz
to
305 MHz, plus selectable wide and narrow measurement bandwidths
of
±100kHz
and±
1.25 kHz respectively. Tuning may be carried
out
using the
instrument's course and fine
tuning
controls
to
regulate
an
internal voltage,
or
it
may
be
accomplished remotely using
an
external voltage. The tuned-in
frequency
is
indicated on a frequency meter, which
for
TV
measurements
is
also provided
with
interchangeable meter
scales
on which American and
European
TV
channels
are
indicated.
The
output
section
of
the 2007
is
a quasi
RMS
voltmeter which
for
carrier measurements
has
voltage sensitivities ranging
from
100
pV
to
100
Volt
full
scale.
For
modulation measurements the meter
is
calibrated in
modulation percentage (0
to
80%)
for
amplitude modulated signals and
frequency deviation
(0
to
80kHz)
for
frequency modulated signals.
Unlike
conventional instruments
of
this
type
the 2007
need
only
be
calibrated at one frequency
for
which
a
built-in
27 MHz reference signal
is
provided. Once calibration
has
been applied
it
is
valid at all
other
frequencies in the measurement range
of
the 2007.
The power supply
of
the 2007
is
completely self contained.
It
may
be
operated
from
either
a mains supply
or
from
five rechargeable nickel
cadmium cells which
are
built-in
along
with
a battery charger. When
fully
charged the
built-in
batteries
will
give
about
8 hours
of
continuous
operation before recharging
is
necessary.
The accuracy and
portability
of
the 2007
will
make
it
especially useful
for
measurements, alignment
or
trouble
shooting on a wide variety
of
radio
and
TV
communications equipment, including transmitting and receiving
antennas. Its high selectivity, and good image and
IF
rejection also makes
it
ideal
for
distortion
measurements.
5
2.
CONTROLS
2.1. MEASUREMENT PROBE
AND
PROBE ACCESSORIES
;;;;;;;
50Q
BNC
Termination
(RZ 0006)
BNC
Connector
(JP
0029)
liiiiiiiiiiiiQ
Blunt
Nose
Test Prod
(JL 0029)
~
Needle Nose
Test Prod
(UR
0124)
,,.•.
·
;
·
--:-
;
~·
,
;
;
i
11
i
'
iiii
···-
~
60 dB
Attenuator
Blunt
Nose
(ZF 0003) Test Prod
(JL 0029)
Fig.2.1. Measurement Probe andprobe accessories
of
the
2007
MEASUREMENT
PROBE:
6
The Measurement Probe ZC 0009 con-
tains a high
input
impedance field
effect
transistor preamplifier
to
prevent load-
ing
of
the measurement source. The
input
to
the preamplifier
is
via a screw
thread
termination
on the body
of
the
probe and accepts the
range
of
probe
accessories shown in Fig.2.1.
To
allow
in situ measurements
to
be
carried
out
on
electronic apparatus the
output
of
the probe
is
via a 1.2 metre long screen-
ed
cable, terminated
with
a BNC out-
put,
which
directly
fits
the PROBE
INPUTsocket
of
the 2007.
60 dB
ATTENUATOR:
50
Q
TERMINATION:
WARNING.
The maximum
input
volt·
age
which may
be
handled
by
the
Measurement Probe
is
100
mV
for
signal
frequencies ranging
from
100kHz
to
305 MHz, whilst at 50
or
60Hz
it
is
250
Volts
and at
DC
it
is
500 V.
The
60
dB
Attenuator
ZF 0003
is
for
attenuation
of
the
input
signal
to
the
Measurement Probe, thereby changing
the maximum
input
voltages marked
around the
VOLTAGE
RANGE switch
of
the 2007
from
mV
to
Volts. The
input
to
the attenuator
is
a screw thread
termination which accepts the
range
of
probe accessories shown in Fig.2.1. The
attenuator push fits
onto
the
·body
of
the Measurement Probe when the screw
thread
input
termination
has
been
fitted
with
a
Blunt
Nose
Test Prod Type
JL
0029
(see
Fig.2.1 ).
This
is
a 50 Q BNC Termination which
screws
directly
onto
the
input
of
the
Measurement Probe and the
60
dB
Attenuator.
It
is
used
to
match the
input
of
the probe
or
Attenuator
to
a
50 Q measurement source.
WARNING.
When
usi~g
the 50 Q
Termination, the maximum
input
volt·
age
is
limited
to
3.5 Volts. This should
not
be
exceeded
as
the Termination
will
be
damaged.
7
22.
FRONT PANEL OF 2007
Input
Bandwidth
"
'!!'
l
-------._-Light
,.-------Frequen
cy Range
Tuning
Ref.
Voltage
Fig.2.2.
Front
panel
of
the
2007
RF
AND
MODULATION
METER: A moving coil indicating meter
with
mirror
back
to
avoid parallax errors.
The meter
has
five
scales,
the functions
of
which
are
as
follows:
8
Voltage
scales.
These
are
situated
immediately above the
mirror
on the
meter. They
are
used
for
voltage
mea-
surements on
RF
signals applied
at
the
input
to
the Measurement Probe when
the carrier modes
of
the METER and LS
switch
are
used.
dB
scale. This
is
situated immediately
below the
mirror
and
is
used
in conjunc-
tion
with
the voltage
scales
when the
"carrier''
modes
of
the METER
AND
LS
switch
are
employed. The
scale
is
POWER SWITCH:
calibrated
from
-
00
to
+10 dB where
10 dB represents
full
scale.
Modulation
scale. This
is
situated
immediately below the dB
scale
and
is
used
for
modulation measurements on
amplitude
or
frequency modulated
signals applied
at
the
input
to
the
Measurement Probe when the
"Mod."
modes
of
the METER
AND
LS
switch
are
used.
The
scale
indicates the degree
of
modulation in %
for
AM
(Amplitude
Modulated) signals,
as
well
as
the fre-
quency deviation in kHz
for
FM
(Fre-
quency Modulated) signals.
Battery scale. This
is
situated below the
modulation
scale
and
is
used
in conjunc-
tion
with
the
"Batt.
Check" mode
of
the POWER SWITCH
to
see
if
the
built-
in batteries
are
charged.
Five position switch
with
the
following
functions:
"Off".
The internal and external power
supplies
are
disconnected
from
the in-
ternal supply lines
of
the instrument.
"Line".
In this mode the instrument
is
powered
from
an
AC main supply which
may
be
connected
to
the AC POWER
INPUT
socket on the rear panel
of
the
instrument.
At
the
same
time the
built-
in nickel cadmium batteries
will
be
automatically recharged.
"Batt.".
The instrument
is
powered
using the
built-in
nickel-cadmium bat-
tery
(see
section 3.1.2). The instrument
may also
be
powered using a 6.3
Volt
battery
connected externally
to
the
REMOTE
TUNING
and EXT.
BATT.
9
ON:
METER
AND
LS SWITCH:
10
socket on the rear panel
of
the instru-
ment
(see
section 3.6.2).
"Charge". With
this
mode selected the
built-in
battery
can
be recharged
by
connecting the AC POWER
INPUT
socket
to
a mains supply. The remaining
circuitry
is
disconnected internally. The
recharge
time
is
approximately 16
hours.
"Batt.
Check". This mode
is
used
to
check whether the
built-in
batteries are
charged.
If
charged, the needle
of
the
RF
AND
MODULATION
METER
should deflect
to
within
the
"Batt."
region at
the
bottom
of
the meter scale.
If
not,
recharge the battery.
A neon indicator lamp which lights
when the
"Line"
and
"Batt."
modes
of
the POWER switch are selected, and
the
measurement
circuitry
of
the instru-
ment
is
powered using internal
or
exter-
nal
power supplies.
In
the
"Line"
mode
the lamp
will
light continuously,
whilst
in the
"Batt."
mode the lamp
will
flash
at regular intervals.
Six position switch
for
selection
of
Carrier and Modulation measurement
modes:
"Carrier".
In the
"AM
Carrier"
(Amp
Ii-
tude Modulated carrier)
or
"FM
Carri-
er"
(Frequency Modulated carrier)
modes, the voltage and dB
scales
of
the
RF
AND
MODULATION
METER may
be
used
for
measurements on the carrier
of
amplitude and frequency modulated
signals.
For
peak voltage measurements
on
TV
signals a "Peak Carrier" mode
is
also provided. In the
"Carrier
AM
and
FM"
modes, the
built-in
loudspeaker
is
connected.
LOUDSPEAKER:
MODULATION
ADJ.:
REF.
VOLTAGE:
SENS.:
"Mod."
In the
"AM
Mod."
(Amplitude
modulated) and
"FM
Mod."
(Frequency
modulated) modes, the percentage
modulation on amplitude modulated
signals and frequency deviation on fre-
quency modulated signals may
be
measured using the modulation
scale
of
the
RF
AND
MODULATION
METER.
In the
"Adj.
Mod."
mode the MODU-
LATION
ADJ. control
is
used
for
cali-
bration
of
the
RF
AND
MODULATION
METER
for
modulation measurements.
In all three
"Mod."
modes the loud-
speaker
is
disconnected.
Volume control
for
the built-in loud-
speaker controlling the gain
of
the
LF
Amplifier
of
the 2007. The control also
serves
as
an
on/off
switch
for
the
LF
Amplifier's
power supply. Therefore in
the
"Mod."
modes
of
the METER
AND
LS
SWITCH
it
should
be
set
to
a
position other than
"LF
Off"
(click-
stop position).
Potentiometer control
for
adjustment
of
the
RF
AND
MODULATION
METER's
pointer deflection when the
"Adj.
Mod."
mode
of
the METER
AND
LS
switch
is
selected
for
calibration
of
the
"AM
and FM
Mod."
modes.
BNC socket supplying at stabilized
2.5
mV
(±
0.5 dB), 27 MHz reference
voltage
for
calibration
of
the deflection
on the RF
AND
MODULATION
METER when the
"Ref"
mode
of
the
VOLTAGE
RANGE switch
is
selected.
Potentiometer control
for
adjustment
of
the internal IF
Amplifier
gain when the
"Ref'
mode
of
the
VOLTAGE
RANGE
switch
is
selected
for
calibration
of
the
11
PROBE INPUT:
FREQUENCY
METER:
VOLTAGE
RANGE:
12
deflection on the RF
AND
MODULA-
TION
METER using the internal refer-
ence
voltage.
BNC
input
socket
for
connection
of
the
output
plug
of
the Measurement Probe.
A moving coil meter
with
interchange-
able meter
scales.
The
scales
provided
are:
SA 0155. This
scale
has
eight frequency
ranges
which
are
calibrated in MHz
to
indicate the frequency
to
which the
2007
is
tuned. The
ranges
are
numbered
and
correspond
to
those
which
may
be
selected
with
the
FREQUENCY
RANGE switch.
SA 0156. This
scale
has
eight
ranges
and
is
calibrated
to
indicate the carrier
as
well
as
the video and audio
modulation
frequencies
of
American
TV
channels.
Each
of
the
ranges
is
numbered and
corresponds
to
those which may
be
selected using the
FREQUENCY
RANGE switch.
SA0157.
This
scale
is
similar
to
SA 0156 except
that
it
is
calibrated
for
European
TV
channels.
To
insert these
scales
the meter may
be
released
by
pushing down and pulling
forward the central clip on
top
of
the
meter. The meter should then
tilt
slight-
ly
forward enabling the
scale
already in
the meter
to
be
slid
out
and a new
scale
to
be
inserted.
Stepped attenuator
for
attenuation in
10 dB steps
of
the signal
to
the
IF
Amplifier
of
the 2007. The values 0.1 -
BANDWIDTH:
LIGHT:
TUNING:
0.3 - l - 3 - 10 -30 -100 marked
around the
knob
are
the maximum
input
voltages
(for
full
scale
deflection
on the RF
AND
MODULATION
ME-
TER) in
mV,
at
the
input
to
the
measurement probe
for
each
knob
set-
ting. When the 60 dB attenuator
is
used
with
the Measurement Probe the values
are
in Volts.
If
the amplitude
of
the signal
is
un-
known,
use
the 100 V knob setting and
decrease the attenuation using the
switch
until
a suitable deflection
is
obtained on the meter. The
"Ref."
mode
of
the switch
is
for
calibration
of
the RF
AND
MODULATION
METER
using the internal reference voltage.
Two
position switch governing the
selec-
tivity
of
the 2007.
"Wide".
In this mode the bandwidth
(within
-3
dB limits)
is
200 kHz.
It
should
only
be
used
for
measurements
at frequencies higher than 6 MHz.
"Narrow".
In
this mode the bandwidth
(within
-3
dB limits)
is
2.5 kHz.
Self resetting
on-off
switch
for
the
meter
scale
illumination when the
"Batt."
mode
of
the
POWER
switch
is
selected.
Two
concentric knobs
for
coarse (inner,
small knob) and fine (outer, large
knob). Frequency tuning
of
the 2007
over the
range
selected using the FRE-
QUENCY RANGE switch. The fre-
quency
is
indicated
by
the
pointer
deflection
of
the FREQUENCY
METER.
13
FREQUENCY RANGE:
2.3. REAR PANEL OF 2007
Fuse
and
Voltage Selector
AC
Power
Input
Eight position switch
for
selection
of
the frequency range over which the
2007 may
be
tuned using its
TUNING
control
knobs. The
ranges
are
numbered
and correspond
to
the numbers
of
the
frequency
or
channel
ranges
on the
scale
used
in the FREQUENCY METER i.e.
1.
0.1-
3.0 MHz
2.
2.5-
8.0 MHz
3.
7.0-
31
MHz
4. 29 55 MHz
5.
50 -105 MHz
6. 100 -160 MHz
7. 155 -225 MHz
8. 220 -305 MHz
Remote Tuning
and
Ext. Battery
Fig.2.3. Rearpanel
of
the
2007
AC
POWER INPUT:
14
Input
socket accepting European
or
American power cables
(B
& K Types
AN 0005
and
AN 0006 respectively)
for
connection
of
the AC line
or
main
supply. The connections
to
this socket
are
shown in Fig.2.4.
Transformer
·shield
and chassis
AC
Supply
172008
Fig.2.4.
AC
POWER
INPUT
VOLTAGE
SELECTOR:
REMOTE
TUNING
AND
EXT.
BATT.
SOCKET:
Voltage selector
for
selection
of
correct
line
or
mains voltage, containing a
250 rnA fuse.
To
remove the fuse,
press
in the central knob containing the fuse
and
turn
it
counter clockwise.
Half
a
turn
should
be
sufficient
to
release
the
knob which may then
be
pulled straight
out.
Behind
the
fuse
are
some slots.
If
a coin
is
pushed
into
the slots and rotated the
voltage selector
will
turn.
When
the
white
line points
to
the voltage
to
be
used, the fuse may
be
replaced and the
instrument
is
ready
for
use.
NOTE.
Verify
the line voltage setting
before
each
use.
A
seven
pin
DIN
socket accepting a
DIN
type
plug {B & K
Type
JP
0703)
for
remote frequency
tuning
and connec-
tion
of
an
external 6.3 V
ott
battery.
It
also
serves
as
an
output
for
the
LF
Amplifier
and Carrier Detector
of
the
2007 enabling
an
external loudspeaker
or
moving coil meter
to
be
connected
for
remote
monitoring
purposes.
For
connections
see
section 3.6.
15
3.
OPERATION
3.1.
PRELIMINARY
3.1.1. Operation Using Mains
or
Line Supply
Before the instrument
is
used
check
that
the
VOLTAGE
SELECTOR on
the rear panel
of
the
instrument
is
set
to
the correct mains
or
line voltage.
If
not
remove the central knob
of
the selector, containing a
250
rnA fuse,
by
simply pressing the knob in and
turning
it
counterclockwise.
Half
a
turn
should
be
sufficient
to
release
the
knob which may then
be
pulled straight
out. Behind the
knob
are
some
slots which
with
the aid
of
a coin may
be
used
to
turn
the selector
so
that
the
white
line points
to
the correct voltage
indication.
Once this adjustment
has
been
made the AC POWER socket
of
the
instrument may
be
connected
to
the mains
or
line voltage supply using
either the European power cable
AN
0005
or
the American power cable
AN
0006.
3.1.2. Operation Using
the
Built-in
Battery Supply
For
operation using the
built-in
battery supply the
"Batt."
mode
of
the
POWER SWITCH should
be
selected. The batteries
are
rechargeable nickel
cadmium cells which when
fully
charged provide
about
8 hours
of
continuous operation.
To
check whether the batteries
are
fully
charged select the
"Batt
. Check" mode
of
the POWER SWITCH. The
pointer
of
the
RF
AND
MODULATION
METER should register
within
the
"Batt."
region at the
bottom
of
the meter
scale.
If
not
the batteries
will
need
recharging. This can
be
done
by
connecting the instrument
to
the mains supply
(see
sec-
tion
3.1.1)
and
selecting the "Charge" mode
of
the POWER SWITCH
to
connect the
built-in
ACto
DC
converter
to
charge the batteries. The
"Line"
mode
of
the POWER SWITCH may also
be
used
for
this purpose,
if
it
is
required
to
carry
out
measurements at the
same
time. The recharge
time
is
approximately 16 hours.
16
In order
to
conserve the batteries when the
"Batt."
mode
is
selected the
meter
scales
are
not
illuminated saving about 6 Watts. However
if
scale
illumination
is
required then the
LIGHT
push-button on the
front
panel
of
the instrument should be pressed.
3.2. REFERENCE ADJUSTMENTS
Before measurements may
be
carried
out
the 2007 should
be
calibrated
using its internal reference voltage.
To
do
this
proceed
as
follows:
1. Carry
out
the preliminary adjustments necessary
(see
section
3.1
).
2.
Fit
the
FREQUENCY
METER
with
the appropriate frequency
or
TV
channel
scale
for
measurements.
3. Connect the
output
of
the Measurement Probe
to
the PROBE
INPUT
socket
of
the 2007.
4. Using
the
screw thread
input
termination
on the body
of
the
Measurement Probe,
fit
the BNC coupler (Probe accessory,
see
Fig.2.1) and plug
it
into
the REF.
VOLTAGE
socket
of
the 2007.
5.
If
not
already selected, select the appropriate
"Line"
or
"Batt."
supply mode
of
the POWER SWITCH. The 2007
is
transistorized and
is
therefore ready
for
use
immediately.
6. Set the controls on the 2007
to:
VOLTAGE
RANGE
"Ref."
METER
AND
LS
SWITCH
"Carrier-AM"
for
measurements on
unmodulated RF
or
amplitude mod-
ulated radio and
TV
(audio
only)
carrier signals.
"Carrier-FM"
for
measurements on
unmodulated RF
or
frequency mod-
ulated radio and
TV
(TV
audio
only)
carrier signals.
17
BANDWIDTH
FREQUENCY
RANGE
"Carrier-Peak"
for
measurement on
TV
video carrier signals.
"Wide"
"7.0-
31"
MHz
Range
3.
7.
With the
SENSITIVITY
control turned
fully
clockwise, adjust the
small
TUNING
knob
for
coarse frequency tuning
until
the
pointer
of
the RF
AND
MODULATION
METER deflects
to
full
scale. This
should occur when
the
pointer
of
the FREQUENCY METER
is
near
to,
or
coincides
with
the arrow on range 3
of
the meter
scale
selected.
8.
Using the
SENSITIVITY
control adjust the
pointer
deflection
of
the
RF
AND
MODULATION
METER
to
half
of
full
scale
and
using the
inner and
outer
TUNING
knobs
for
course and fine frequency
tuning
adjust the deflection on the meter
to
peak. Finally adjust the
SENSITIVITY
control
so
that
the
pointer
of
the RF
AND
MODULA-
TION
METER coincides
with
the arrow on the
top
scale
of
the meter.
The 2007
is
now
calibrated
for
measurements and therefore the
Measurement Probe may
be
disconnected
from
the REF.
VOLTAGE
socket.
3.3. R.F. CARRIER VOLTAGE MEASUREMENTS
Using the
"Carrier"
modes
of
the METER
AND
LS
SWITCH, voltage
measurements may
be
carried
out
on unmodulated RF signals
as
well
as
on
the modulated carriers
of
radio and
TV
signals.
18
To
make these measurements proceed
as
follows:
1.
Carry
out
the
calibration procedure described in section 3.2.
2.
Set the controls on the 2007
to:
VOLTAGE
RANGE
METER
AND
LS SWITCH
"100"
"Carrier-AM"
For
measurements on
unmodulated
RF
or
amplitude
modulated radio and
TV
(audio
only)
carrier signals. Also
for
TV
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